Sun tracking solar energy collection systems include hardware for automatically adjusting the position of solar energy collecting devices to track the sun as it moves across the sky. Some of these sun tracking systems include a single row or multiple rows of solar energy collection devices supported on a pivoting shaft (or torque tube). A number of tube sections can be connected together to form an elongated torque tube that extends along a horizontal axis.
A drive mechanism is typically connected to the torque tube at the center of the span of the torque tube. The drive mechanism for a single torque tube can be, for example, an electric servomotor slewing drive mounted on one of the piles that support the torque tube. Solar collection devices, such as un-concentrated photovoltaic modules, concentrated photovoltaic modules, or thermal solar collection devices, are mounted to the torque tube along its span. The drive mechanism is periodically activated to rotate the torque tube so that the solar collection devices track movement of the sun during the course of a day. During periods when it is not activated, the drive mechanism holds the torque tube at its current rotated position.
Some sun tracking solar energy collection systems make use of a number of rows arranged parallel to one another, with a master motor device that is connected by links to the drive mechanism for each torque tube of the parallel rows. With this type of “ganged” system, a reduced number of motorized drive devices are needed. The drive mechanisms linked to the master drive motor are typically located at the center of the span of their associated torque tubes.
Row level actuated sun tracking solar energy collection systems utilizing torque tubes are flexible structures, and the solar energy collecting devices connected to the torque tube are typically in the form of panels that act as large airfoils when subjected to high winds. As a result, these systems are vulnerable to resonant motion in high wind conditions because the row is only locked in rotation at the center, where the drive mechanism is located.